Filmed at Red Rock Canyon, AZ, and at rental stages at the California Tiffany Studios, Tombstone Canyon was the fifth of eight low-budget westerns Ken Maynard would make for independent producer E. W. Hammons' K.B.S Productions. Searching for his parents' killers, Ken goes up against a mysterious masked villain, "The Phantom," whose shrill cry of vengeance sends shivers through the settlers in Tombstone Canyon. But as Ken quickly learns, "The Phantom" (Sheldon Lewis) only kills men working for nasty Alf Sikes (Frank Brownlee). The latter attempts to blame Ken for the recent slayings of his henchmen but the newcomer manages to prove otherwise. In the end, there is a huge surprise in store for our intrepid hero, whose parentage is not quite what he has always believed. Although technically crude and directed with the usual lethargy by Alan James (formerly Alvin J. Neitz), Tombstone Canyon is at times beautiful to look at and presents a legendary cowboy star at the height of his game.
by Hans J. Wollstein synopsis